Suprabasal integrin expression in the epidermis of transgenic mice results in developmental defects and a phenotype resembling psoriasis

Abstract

Integrin expression is normally confined to the basal layer of the epidermis, but when epidermal homeostasis is perturbed, the receptors are also expressed by suprabasal, differentiating keratinocytes. We have used the involucrin promoter to express functional human integrin subunits α 2, α 5, and β 1 in the suprabasal epidermal layers of transgenic mice. In mice expressing α 5 or β 1 alone or α 2 β 1 or α 5 β 1, heterodimers, there were hair and whisker abnormalities and a failure of eyelid fusion. In addition, mice expressing β 1 alone or in combination with α 2 or α 5 exhibited epidermal hyperproliferation, perturbed keratinocyte differentiation, and skin inflammation, all of which are features of a common human skin disease, psoriasis.